Gun-barrel for shotguns.



PATETED 00T. 16, 1906.

W. L. ROBBDBB.

GUN BARREL POR SHOTGUNS.

APPLICATION FILED 8EPT.12. 1905.

l! isili m WW. M M

cT TURNEY UNITED STATES PATENT OFFIOE.

WILLIAM L. ROBEDEE, OF ELBRIDGE, NEW YORK, ASSIGNOR OF ONF- HALF TO RAY M. OORNVVELL, OF SYR-AGUSE, NEW YORK.

GUN-BARREL FOR SHOTGUNS.

Specification of Letters Patent.

Patented Oct. 16, 1906.

Application iiled September 12,1905. Serial No. 278,104.

To all?, when@ it may concern,.-

Beit known that I, WILLIAM L. ROBEDEE, of Elbridge, in the county of Onondaga, in the State oi' New York, have invente new and useful Improvements in Gun-Barrels for Shotguns, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

This invention relates to certain improvements in gun-barrels for Shotguns, in which the barrel is provided with a continuous series of taper bores progressively but smoothlyT merging one into the other at gradually (though slightly) increasing angles with the axis of the barrel, thereby constituting what may be termed a series choke bore as d istinguished from a continuous single taper or choke, for the purpose of concentrating the charge at the target within a smaller area than has heretofore been practiced.

I am aware that it is common to reduce or choke the bore at the muzzle; but I believe that I am the first to provide a barrel with a series-choke bore produced by a series of tapers all converging toward the muzzle at progressively-increasing 'angles with the axis.

In several comparative tests with my series-choke barrel and the ordinary singlechoke barrel I find that with my barrel an average of more than ninety per cent. of the charge is concentrated within a circular target area of thirty inches diameter at forty yards distance as against seventy-five per cent. with an ordinary single-choke-bore gun of the same dimensions but single choke and under the same distance and target conditions. This enables the user of my improved barrel to not only concentrate a greater percentage oi the full charge within a smaller target area than is practicable with a single-choke barrel, but also proportionately increases the carrying distance of the efl'ective charge, the advantages of which are clearly manifest.

In the drawings, Figure 1 is a longitudinal sectional view of a portion of a gun-barrel embodying the features of my invention. Fig. 2 is a transverse sectional view taken on line 2 2, Fig. l.

In. order that my invention may be clearly understood, 'Il have shown about eight-inches olthe muzzle end of my improved barrel A as provided with a series oll tapers a, e, which begin about six inches back of' the mur/.zh of the barrel and merge smoothly one into th othcr,so that all 0I the tapers converge t( ward the muzzle at progressively-increasin angles with the axis of the barrel. Thee tapers are considerably exaggerated in tk drawings for the urpose of more clear] bringing out this eature of my inventioi and 1t will be seen that each taper is of sul stantially the same length, the larger end 1 the rst taper a being ofthe saine diamet as that of the rest of the main portion of tl bore toward the breech of the barrel, and tl larger end of the taper b is identical in dian eter with that of the smaller end ol' the tap a., while the larger end of the taper c is oi tl saine diameter as that of the smaller end 1 the taper I), so that these several tapers a,

and c gradually diminish toward the muzz of the barrel, but at increasing angles wil the axis of the said barrel, for the purpose gradually compressing and at the same tin slightly elongating the charge in its trans to and discharge from the muzzle of the ba rel, in which condition it is carried a const able distance without spreading, and, in fac in the tests which I have made I find that a distance of forty yards fully ninety p cent. of the charge is concentrated within target area having a diameter of less ths thirty inches, while with an ordinary sing choke under the same conditions I have bee unable to concentrate more than seventj iive per cent. within the saine target are This shows conclusively that with my in proved series-choke barrel I am enabled nl only to concentrate a larger percentag (nearly all) of the charge within a conipar tively sm all area at a given distance, but I a also enabled to carry the charge in a mo concentrated condition a greater distan than with a single choke such as is now i common use.

I have shown each taper as being aboi two inches in length simply because the gr with which my experiments were made w bored in this manner; but I may iind up( further experiment that a greater' or le length of taper may be equally servieeah or superior in carrying out the objects of n invention. '.llherelorel do not wish to lin myself to the exact portion olz the barrel which these series tapers are bored Furth than that they must merge one into ll lr at progressively-increasing angles wi the axis of the barrel, thereby producing rel, and the taper of the bore-section inter what may be termed a continuous seriesosed between said other two bore-section; choke bore. being of less ta er than the bore-section adj a What I claim is cent the breecl. 5 A gun-barrel having a series-choke bore In Witness whereof I have hereunto se formed by a series of tapered bore-sections my hand this 8th day of September, 1905.

each of substantially the same length, the ta- WILLIAM L. ROBEDEE. per of the bore-section forming the muzzle of Witnesses: the barrel being greater than the ta er of the I-I. E. CHASE, [o bore-section adjacent the breech o the bar- HOWARD P. DENISON. 

